Improving the dyeing properties of cellulosic textiles by treatment with formaldehyde and a guanidine salt of an alpha-beta unsaturated carboxylic acid



Patented Mar. 11, 1947 HHPROVING THE DYEING PROPERTIES OF CELLULOSIC TEXTILES BY TREATMENT WITH 'FORMALDEHYDE AND A GUANI- DINE SALT OF AN ALPHA-BETA UNSATU- RATED CARBOXYLIC ACID James Hutchison MacGregor, Backing Braintree, England, assiznor to Courtaulds Limited, London, England, a British company No Drawing. Application May 6, 1944, Serial No. 534,529. In Great Britain July 22, 1943 2 Claims.

This invention relates to the treatment of cellulosic textile materials and in particular to improving the dyeing affinity of such materials.

It has already been proposed in British specification No. 433,143 to treat cellulosic fibres with formaldehyde condensation products obtained by condensing formaldehyde with dicyandiamide, guanidine or heat-treated urea and to dye the treated fibre with wool or silk dyestufis. It has also been proposed in British specification No. 450,516 to produce difierential colour efiects upon textile materials by locally impregnating with a nitrogenous synthetic resin and subsequently condensing to produce the synthetic resin on the material and applying a dyestufi to the material. Among the large number of synthetic resins cited in the specification are the compounds of formaldehyde with guanidine and its derivatives. In

my prior British patent specification No. 549,214 I have described the improvement of the dyeing afiinity of cellulosic textile material by treating it with an aqueous solution containing formaldehyde and a guanidine salt of a long chain aliphatic dicarboxylic acid, either as such or in the form of their water-soluble condensation product and then heating the material to convert the guanidine salt and formaldehyde into a waterinsoluble condensation product. The affinity of the material for many classes of dyestuffs is improved by this process.

I have now found that the aiilnity of undyed cellulosic textile material for chrome dyestufis applied by the metachrome or after-chrome process and for such classes of dyestufis a acid wool, direct cotton, solubilized vat (i. e. sulphuric ester salts of the leuco vat dyestuffs), aqueous dispersions of insoluble aminoand hydroxy-azo compounds and of insoluble aminoand acylaminoanthraquinones is improved if the material is treated prior to dyeing with an aqueous solution containing formaldehyde and a guanidine salt of an unsaturated carboxylic acid, such as an aliphatic or aromatic monobasic or dibasic acid either as such or in the form of their watersoluble condensation product and then converting to the water-insoluble condensation product. The process can be carried out under acid, neutral or alkaline conditions, and if desired a catalyst, such for example as ammonium thiocyanate, may be present.

As examples of suitable guanidine salts which may be used in carrying out the process of the present invention I may mention guanidine acrylate, guanidine methacrylate (salt of guanidine and alpha-methylacrylic acid) guanidine styrylacrylate, guanidine alpha-chloroacrylate, guanidine maleate and guanidine cinnamate.

Cellulosic mterial when treated according to 2 the present invention gives dyeings with chrom dyestufis of the same depth of shade as similar dyeings on wool. A good afiinity for chrome dyestuffs can be obtained on cellulosic material by the process of the present invention even when the impregnation with formaldehyde and the guanidine salt of an unsaturated carboxylic acid is carried out under alkaline conditions whereas in order to obtain a good aflinity for chrome dyestuffs with other guanidine salts and formaldehyde the treatment must be carried out in presence of ammonium thioeyanate as acid catalyst.

Further the light-fastness of dyeings produced by acid wool, direct cotton and chrome dyestuffs on cellulosic material treated according to the present invention is equal to or even better than corresponding dyeings on wool.

The treatment according to this invention, in addition to improving the affinity of the cellulosic material for the dyestufis hereinbefore mentioned, also imparts an improved, resilient, soft handle, and this improved handle persists after dyeing. Cellulosic material treated according to the present invention possesses very good fastness to crabbing, this is particularly the case when the treating solution used is in the alkaline pH range, for example, at a pH of 8.0.

The following examples illustrate the present invention without the invention being limited to these examples. The percentage of the compounds used is based on the weight or the fibre being treated.

Example 1 Gu anidine-methacrylate (H2N.%.NH2-HO O C.C (CHa)=CHz) is prepared at room temperature by the careful addition over a period of 15 minutes of a concentrated aqueous solution of 1 mol of guanidine carbonate to an ethanol solution of 2 mols of methacrylic acid (stabilised with hydroquinone). After filtering, the filtrate is concentrated and the guanidine methacrylate obtained as an almost colourless crystalline product, which is readily soluble in warm water.

Viscose staple fibre is soaked at ordinary room temperature in an aqueous solution, the pH of which has been adjusted to 8.0, containing 3 parts of guanidine methacrylate and 16 parts of 40 per cent formaldehyde in parts of solution. After saturation, the staple fibre is hydroextracted until it contains approximately its own weight of liquid, then dried at under 100 centigrade and heated at centigrade for 10 minutes. It is then entered at 60 centigrade along with an equal weight of secured wool, into 40 volumes of a, dyebath containing 2 per cent of Erlochrome Azurol B (Colour Index 720), 2 per cent of potassium chromate and 4 per cent of ammonium sulphate. The temperature of the dyebath is then raised to 95 centigrade and dyeing continued at this temperature for 1 /4 hours. After removing from the dyebath, rinsing and which has been adjusted to 8.0, containing 3 drying it is found that both the animalized staple centrated and guanidine alpha-chloroacrylate.

obtained as an almost colourless crystalline product, readily soluble in warm water.

Viscose staple fibre is soaked at ordinary room temperature in an aqueous solution, the pH of which is 3.4, containing 3 parts of guanidine al- I pha-chloroacrylate and 16 parts of 40 per cent formaldehyde in 100' parts of solution. After saturation, the staple fibre is hydroextracted until it contains approximately its own weight of liquid, then dried at under 100 centigrade, and heated at 140 centigrade for minutes. It

is then entered, along with an equal weight of scoured wool, into 40 volumes of a dyebath at 60 centigrade containing 6 per cent of Eriochrome Black T (Colour Index No. 203) and 2 per cent of acetic acid. The temperature of the dyebath is raised to 95 centigrade and dyeing continued at this temperature for 30 minutes. 2 per cent of formic acid is then added and dyeing continued at the same temperature for a further 30 minutes. Finally, 2 per cent of sodium dichromate is added and the dyeing completed after another 30 minutes at 95 centigrade. A full shade of black is obtained on both fibres which are dyed to approximately the same depth.

Example 3 is prepared at room temperature by the careful addition over a period of 15 minutes of a concentrated aqueous solution of 1 mol of guanidine carbonate to an ethanol solution of 2 mols of styrylacrylic acid. After filtering, the filtrate is concentrated and guanidine styrylacrylate obtained as a colourless crystalline product readily soluble in water but readily decomposed on the addition of acid to its aqueous solutions. For this reason it is necessary to use formaldehydeguanidine styrylacrylatesolutions in an alkaline pH range.

Viscose staple fibre is soaked at ordinary room temperature in an aqueous solution, the pH of parts of guanidine styrylacrylate and 16 parts of 40 per cent formaldehyde in 100 parts of solution. After saturation the staple fibre is hydroextracted until it contains approximately its own weight of liquid, then dried at under 100"- centigrade and finally heated at 140 centigrade for 10 minutes. The so-treated staple fibre along with an equal weight of scoured wool is entered at 60 centigrade into 40 volumes of a dyebath containing '2 per cent of Solochrome Brown M. O. S. (Imperial Chemical Industries Ltd.), 2 per cent of potassium chromate and 4 per cent of ammonium sulphate. The temperature of the dyebath is then raised to centigrade and dyeing continued at this temperature for 1% hours. A deep shade of brown of practically the same depth is obtained on both fibres.

Example 4 Viscose staple fibre is soaked at ordinary room temperature in an aqueous solution, the pH of which is 4.5, containing 3 parts of guanidine cinnamate and 16 parts of 40 per cent formaldehyde in parts of solution. After saturation, the staple fibre is hydroextracted until it contains approximately its own weight of liquid,

then dried at under 100 centigrade and finally heated at Centigrade for 10 minutes. The so-treated staple fibre is then entered at 60 centigrade into 40 volumes of a dyeb'ath containing 1 per cent of Coomassie Navy Blue 2RNS (Colour Index No. 289), and 2 per cent of acetic acid based on the Weight of fibre. The temperature is raised over a period of an hour to 95 centigrade and dyeing continued for another /2 an hour at this temperature, when 0.25 per cent of potassium dichromate is added,

and dyeing continued for a further /2 an hour at 95 centigrade. The staple fibre is dyed a full navy shade of equal light-fastness to a similar dyeing on wool.

What I claim is:

1. A process of improving the dyeing afllnity of cellulosic textile material and imparting a 80f S y handle thereto, which comprises treating the material before dyeing with an aqueous solution containing formaldehyde and a guanidine salt of an alpha-beta unsaturated carboxylic acid which is devoid of amino groups, and thereafter converting the mixture to a waterinsoluble condensation product.

2. A process of improving the dyeing affinity of cellulosic textile material and imparting a soft silky handle thereto, which comprises treat: ing the material before dyeing with an aqueous solution containing formaldehyde and a guanidine salt of an alpha-beta unsaturated carboxylic acid which is devoid of amino groups, in the form of their Water-soluble condensate and thereafter converting thewater-soluble condensate into a water-insoluble condensation product.

- JAMES HUTCHISON MACGREGOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

